1. Field
The present disclosure relates generally to analog to digital converters and in particular to a method and apparatus for converting analog input into digital output. More particularly, the present application is directed to a method and apparatus for analog to digital converters with dynamically reconfigurable conversion resolution.
2. Background
An analog signal is a time continuous signal having some varying feature of the signal that conveys information. A digital signal conveys information using discrete values rather than variations in a continuous signal. An analog to digital converter (ADC) is a device that converts an input analog voltage to a digital output.
There are currently many existing topologies for analog to digital converters. Each analog to digital converter topology is specifically configured for the number of bits of resolution generated during the conversion. The bit resolution of a digital signal refers to the bit depth or level of detail in the discrete, sampled digital signal output.
Although analog to digital converters generate the conversion data in parallel “N” bit wide format, a parallel to serial converter function is often included to simplify the electronic interface. Manufacturers of analog to digital converters will often produce multiple parts within the same family with different numbers of bits of resolution. Typical converter resolutions are 8 bit, 10 bit, 12 bit, 14 bit, 20 bit, and so forth using serial output computer buses, such as serial peripheral interface (SPI) or inter-integrated circuit (12C). The pinouts of these analog to digital converters are standardized and allow interchangeability of parts. Thus, if a user wishes to change the bit resolution of serial digital output generated by an analog to digital converter, the user manually changes the parts having a first number of bits of resolution with parts that will produce output having a different number of bits of resolution. In this manner, the user can manually replace analog to digital converter parts with parts in the same family that has the identical electronic interface but produces a different number of bits of resolution.
The task of manually replacing parts associated with analog to digital converters each time a user wants to change the bit resolution of output digital signal is cumbersome, time consuming, and inefficient. Moreover, analog to digital converters with higher resolution often require a longer conversion period between the time that the analog voltage is sampled and the digital data is available for readout. Since analog to digital converters are often used in digital control loops, any latency during the conversion process is detrimental to the frequency response of the loop.
Trading resolution for speed requires physically replacing the analog to digital converter. In other words, if it is desirable to lower the resolution for the sake of increasing the conversion speed, the user may have to manually replace the higher resolution analog to digital converter with a lower resolution analog to digital converter. Also, high speed analog to digital converters frequently require significant amounts of electronic circuitry and consume a significant amount of power as compared to slower analog to digital converters.
Accordingly, there is a need for a method and apparatus for an analog to digital converter with dynamically reconfigurable conversion resolution, which overcomes the problems discussed above. Embodiments of the disclosure are intended to satisfy this need.